Populate the client website template with catalog feature flags.

Extract always-on public/portal/UTM plus optional email_sms, directmail, blog, payments, social, and social_ai so new client sites can be bootstrapped from this seed.

Refs #1
Refs #2

Co-authored-by: Cursor <cursoragent@cursor.com>

site/payments/models.py

@@ -0,0 +1,52 @@
+from decimal import Decimal
+
+from django.conf import settings
+from django.db import models
+
+from contacts.models import Contact
+from core.models import TimeStampedModel, UUIDPrimaryKeyModel
+
+
+class Invoice(UUIDPrimaryKeyModel, TimeStampedModel):
+    class Status(models.TextChoices):
+        DRAFT = "draft", "Draft"
+        OPEN = "open", "Open"
+        PAID = "paid", "Paid"
+        VOID = "void", "Void"
+        UNCOLLECTIBLE = "uncollectible", "Uncollectible"
+
+    number = models.CharField(max_length=32, unique=True)
+    contact = models.ForeignKey(
+        Contact,
+        on_delete=models.PROTECT,
+        related_name="invoices",
+    )
+    description = models.CharField(max_length=255)
+    amount = models.DecimalField(max_digits=10, decimal_places=2)
+    currency = models.CharField(max_length=8, default="usd")
+    status = models.CharField(
+        max_length=16, choices=Status.choices, default=Status.DRAFT
+    )
+    due_date = models.DateField(null=True, blank=True)
+    stripe_invoice_id = models.CharField(max_length=255, blank=True)
+    stripe_checkout_session_id = models.CharField(max_length=255, blank=True)
+    hosted_invoice_url = models.URLField(blank=True)
+    paid_at = models.DateTimeField(null=True, blank=True)
+    created_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="created_invoices",
+    )
+    notes = models.TextField(blank=True)
+
+    class Meta:
+        ordering = ["-created_at"]
+
+    def __str__(self) -> str:
+        return f"{self.number} · {self.contact} · {self.amount} {self.currency}"
+
+    @property
+    def amount_cents(self) -> int:
+        return int((self.amount * Decimal("100")).quantize(Decimal("1")))